This invention relates to a moisturizing composition, a base containing the same, and a cosmetic or external preparation containing the moisturizing composition.
It is well-known that moisture is deeply involved in various products such as cosmetics, pharmaceuticals, agricultural chemicals and foods, and moisturization thereof is one of important functions for the quality of the products. It is also well-known that moisture is deeply involved in the retention of youthful skin, and the moisturization of skin is one of important functions for the quality of cosmetics. As known moisturizing agents, particularly known moisturizing agents used in cosmetics or external preparations, there are polyhydric alcohols such as glycerol, 1,3-butylene glycol and sorbitol, and further pyrrolidonecarboxylate salts, lactate salts, etc. In recent years, sodium hyaluronate produced by a microorganism has come to be used.
Moisturizing agents also play an important role to work as an agent retaining the moisture of cosmetics or external preparations themselves and thereby contribute to the retention of the stability of the system. Trihydric or more polyhydric alcohols such as glycerol and sorbitol have excellent moisturizing properties and moisture retainability, and further in view of their safety, stability, prices, etc., are used as most general purpose moisturizing agents.
As to requirements which moisturizing agents should have, it is desirable that they are not influenced by environmental conditions (temperature, humidity, wind, etc.), and particularly can retain moisture for a long time regardless of the surrounding humidity. However, in the case of any moisturizing agent, the amounts of the absorption and release of moisture are influenced by the surrounding humidity because of its vapor pressure. In the case of glycerol, for instance, its equilibrium moisture content at 25xc2x0 C. is 60% when the relative humidity is 75%, and 15% when the relative humidity is 33%, and in the case of sorbitol, its equilibrium moisture content at 25xc2x0 C. is 50% when the relative humidity is 75%, and 5% when the relative humidity is 33%, and their moisture contents are influenced by the degree of the surrounding relative humidity.
Thus, there is a problem that when the surrounding humidity is low, the moisturizing agent itself releases the retaining moisture and the amount of moisture retained is lowered. Also when cosmetics or external preparations containing moisturizing agents are used, as understood from the above, moisture is lost from the skin with time lapse under low humidities, and the moisturizing function is lowered. Therefore, as to moisturizing agents, it is necessary that the evapotranspiration of moisture under low humidity environments is slow.
This invention has been made in view of the above problems, and aims to provide a moisturizing composition excellent in moisturizing properties and stability, bases based thereon, and a cosmetic or external preparation containing the moisturizing composition.
The above object has been attained by
(1) a moisturizing composition comprising a trihydric or more water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol, wherein lecithin: the trihydric or more water soluble polyhydric alcohol+3-methyl-1,3-butylene glycol=1:1,000 to 1:1 (weight ratio) and the trihydric or more water soluble polyhydric alcohol:3-methyl-1,3-butylene glycol=1:10 to 20:1 (weight ratio),
(2) A viscous or gel-like base which comprises the moisturizing composition of the above (1) having compounded therein an oily substance.
(3) An oil-in-water type emulsion base which comprises the moisturizing composition of the above (1) having compounded therein an oily substance and water.
(4) A solubilized base which comprises the moisturizing composition of the above (1) diluted with water.
(5) A cosmetic which comprises the moisturizing composition of the above (1) and other raw material(s) for cosmetics.
(6) An external preparation which comprises the moisturizing composition of the above (1) and other raw material(s) for external preparations.
In the above, the moisturizing composition can further contain water in an amount of more than 0% by weight but up to 50% by weight of the total weight of the trihydric or more water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol. For displaying remarkable moisturizing properties, the moisturizing composition desirably has polarizability. The above trihydric or more water soluble polyhydric alcohol is preferably glycerol and/or sorbitol. The lecithin is preferably hydrogenated lecithin in view of oxidation stability.
The invention is further detailedly described below.
As lecithin constituting the moisturizing composition of the invention, there can be used soybean lecithin or egg yolk lecithin, before all else, which is available as a usual commercial product or reagent, and purified lecithin or fractionated lecithin obtainable by subjecting soybean lecithin or egg yolk lecithin to purification operation(s) such as solvent fractionation, extraction and/or fractionation to remove neutral oily matter as sufficiently as possible, or the like. For rapidly dissolving lecithin in a trihydric or more water soluble polyhydric alcohol, purified lecithin wherein neutral oily matter is removed is preferred. Lecithin constituting the moisturizing composition of the invention is assumed to further include hydrogenated lecithin and lysolecithin. Lecithin, in many cases, has an unsaturated fatty acid chiefly at the 2-position of glycerol constituting it, and one obtained by converting it, at least partially, to a saturated fatty acid is hydrogenated lecithin. The degree of hydrogenation in the hydrogenated lecithin is not particularly limited, but it is desirable in view of oxidation stability that it is 45 to 100%, preferably 80 to 100%. Preferred as lysolecithin is one having a low hydrolysis degree, i.e. deacylation degree (e.g., one having a hydrolysis degree of 70% or less). Lysolecithin having a high hydrolysis degree (e.g., one having a hydrolysis degree of more than 70%) can also be used in the invention, but when used, it is preferred to use it together with usual lecithin and make the mixing ratio of such lysolecithin 80% by weight or less based on the usual lecithin. As lecithin used in the invention including even hydrogenated lecithin and lysolecithin, such lecithin that the fatty acid constituting it is not a single fatty acid (ones derived from nature as exemplified above fall under this category) is preferred, and synthetic phosphatidylcholine having a single fatty acid as an constituent is undesirable because when it is used in place of the lecithin in the moisturizing composition of the invention, there is a tendency that precipitate deposits.
The trihydric or more water soluble polyhydric alcohol constituting the moisturizing composition of the invention is not particularly limited, and there can be used, as representative ones, glycerol, sorbitol, diglycerol, triglycerol, polyglycerol, erythritol, pentaerythritol, glucose, galactose, fructose, sucrose, maltose, xylose, xylobiose, reduced oligosaccharides, etc. These can be used alone or in combination of two or more. Preferred among them are glycerol and sorbitol.
As to 3-methyl-1,3-butylene glycol constituting the moisturizing composition of the invention, it is convenient to utilize commercial products (e.g., one made by KURARAY CO., LTD.). A composition comprising 3-methyl-1,3-butylene glycol, a trihydric or more water soluble polyhydric alcohol and lecithin (the moisturizing composition of the invention), whose characteristic lies in containing 3-methyl-1,3-butylene glycol, has a remarkably enhanced moisturizing characteristic, compared with a composition not containing 3-methyl-1,3-butylene glycol (usual compositions), as illustrated in the later-described examples and comparative examples.
In the moisturizing composition of the invention, it is necessary that the ratio (weight ratio) of lecithin the trihydric or more water soluble polyhydric alcohol+3-methyl-1,3-butylene glycol is 1:1,000 to 1:1, and the ratio is preferably 1:200 to 1:1, more preferably 1:50 to 1:2. When the weight ratio of lecithin to the trihydric or more water soluble polyhydric alcohol+3-methyl-1,3-butylene glycol is less than 1/1,000, the moisturizing properties of the moisturizing composition is insufficient, and when the ratio is more than 1/1, the lecithin cannot uniformly dissolve in the composition and insoluble matter deposits.
In the moisturizing composition of the invention, it is also necessary that the ratio (weight ratio) of the trihydric or more water soluble polyhydric alcohol:3-methyl-1,3-butylene glycol is 1:10 to 20:1, and the ratio is preferably 1:7 to 20:1, more preferably 1:4 to 10:1. When the amount of 3-methyl-1,3-butylene glycol is larger than that of the case where the weight ratio of the trihydric or more water soluble polyhydric alcohol:3-methyl-1,3-butylene glycol is 1:10, a tendency enlarges that the lecithin cannot stably dissolve in the trihydric or more water soluble polyhydric alcohol and precipitate is formed at room temperature (e.g., 20xc2x0 C.) to a low temperature (e.g., 5xc2x0 C.). When the amount of 3-methyl-1,3-butylene glycol is smaller than that of the case where the weight ratio is 20:1, the moisturizing composition of the invention does not become high viscous and moisturizing characteristics do not come to a satisfiable degree.
The moisturizing composition of the invention can be substantially nonaqueous, or can further contains water in an amount of more than 0 weight % but up to 50 weight % of the total weight of the trihydric or more water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol. Usually, in commercial lecithins, water of the order of 0.1 to 3% by weight is contained, and in trihydric or more water soluble polyhydric alcohols, 0.1 % by weight or more water is contained (among commercial products, there are even water-containing products such as glycerol having a water content of 0.1 to 20% by weight and sorbitol having a water content of 30% by weight), and in 3-methyl-1,3-butylene glycol, water of the order of 0.1 to 2% by weight is contained. Therefore, in preparation of a moisturizing composition of the invention which contains water, there is a case where water does not need to be added. When the trihydric or more water soluble polyhydric alcohol is a solid saccharide or sugar alcohol (sucrose, glucose, fructose, sorbitol, etc.), it is desirable to add water in an amount of about 10% by weight to about 50% by weight of the total weight of the trihydric or more water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol and uniformly dissolve the solid.
It is preferred that the moisturizing composition of the invention has polarizability. By making the moisturizing composition of the invention a composition having polarizability, it comes to exhibit remarkable moisturizing characteristics.
It is surmised that when the moisturizing composition of the invention contains water or water is compounded into the composition, by the interaction of the coexisting respective components, lecithin takes a specific association structure and high viscous liquid crystals are formed, and thereby the evapotranspiration of water from the composition is inhibited.
There is no particular limitation about processes for preparing the moisturizing composition of the invention, but the composition can be prepared, for example, by stirring a trihydric or more water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol, and, when needed, water, if necessary under heating, to make the mixture a uniform solution.
The invention also relates to a viscous or gel-like base which comprises the moisturizing composition of the invention having compounded threrein an oily substance. This viscous or gel-like base can be used as a base for viscous or gel-like products on which moisturizing properties are needed.
As the oily substance, there can be used, without particular limitation, hydrocarbons, esters, fats or oils, waxes, higher fatty acids, higher alcohols, silicone substances, sterols, resin saccharides, etc. As examples of them, there can be mentioned liquid petrolatum, isoparaffin, petrolatum, squalane, isopropyl myristate, octyldodecyl myristate, cetyl isooctylate (cetyl 2-ethylhexanoate), glyceryl triisooctylate (glyceryl tri-2-ethylhexanoate), glyceryl tricaprylate, diisooctylic acid neopentyl glycol ester (di-2-ethylhexanoic acid neopentyl glycol ester), diisostearyl malate, isononyl isononanoate (3,5,5-trimethylhexanoic acid 3,5,5-trimethylhexyl alcohol ester), cholesteryl 12-hydroxystearate, mono-to hexaisostearic acid dipentaerythritol esters using isostearic acid made by Emery Industries, Inc., isooctyl o, m or p-methoxycinnamate, eucalyptus oil, soybean oil, cotton seed oil, sesame oil, rice germ oil, rice bran oil, safflower oil, sunflower seed oil, palm oil, olive oil, jojoba oil, macadamia nuts oil, avocado oil, castor oil, evening primrose oil, turtle oil, mink oil, orange roughy oil, lanolin, myristic acid, palmitic acid, stearic acid, oleic acid, 12-hydroxystearic acid, behenic acid, stearyl alcohol, oleyl alcohol, cetanol, lanolin alcohol, paraffin wax, microcrystalline wax, ceresin wax, beeswax, carnauba wax, candelilla wax, shellac wax, soybean hardened oil, rapeseed hardened oil, glyceryl tristearate, rosin, cholesterol, phytosterol, dimethyl polysiloxane, methyl phenyl polysiloxane, essential oil components originated in animals or plants, etc. They can be used alone or in combination of two or more.
In the viscous or gel-like base of the invention, it is suitable that the compounding amount of the oily substance is more than 0 times by weight but up to 10 times by weight, preferably 0.001 to 5 times by weight the total amount of the trihydric or more water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol in the moisturizing composition. When the compounding amount is more than 10 times by weight, the moisturizing composition separates.
There is no particular limitation about processes for preparing the viscous or gel-like base of the invention, and it can, for example, be obtained by compounding the oily substance into the moisturizing composition under stirring.
The viscous or gel-like base of the invention can be used as a base for various viscous or gel-like products. As such viscous or gel-like products, there can be mentioned cosmetics (creams, cleansing gel, moisture gel, etc.), external preparations (ointments, etc.), agricultural chemicals, etc.
The invention also relates to an oil-in-water type emulsion base which comprises the moisturizing composition of the invention having compounded threrein an oily substance and water. As the oily substance used in this oil-in-water type emulsion base, there can be used the same oily substances as described in the viscous or gel-like base of the invention, and its compounding amount can also be the same as therein.
It is suitable that the total compounding amount of water in the oil-in-water type emulsion base of the invention is 0.1 to 100 times by weight, preferably 0.1 to 20 times by weight the total amount of the water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol in the moisturizing composition. When the compounding amount is less than 0.1 times by weight, the resultant base does not become an oil-in-water state, and when it is more than 100 times by weight, the effects of the invention cannot be expected. It is possible to previously compound, into this water, water soluble or dispersible component(s) such as known surfactant(s) or moisturizing agent(s).
There is no particular limitation about processes for preparing the oil-in-water type emulsion base of the invention, and it can, for example, be obtained by compounding the oily substance and water into the moisturizing composition under stirring, or by compounding water into the above viscous or gel-like base under stirring.
The oil-in-water type emulsion base of the invention can be used as a base for oil-in-water type emulsion preparations, etc. As such oil-in-water type emulsion preparations, there can be mentioned cosmetics (liquid cream, cream, skin lotion, etc.), etc.
The invention also relates to a solubilized base which comprises the moisturizing composition of the invention diluted with water. It is suitable that the total compounding amount of water in this solubilized base is 0.5 to 100 times by weight, preferably 0.5 to 20 times by weight the total amount of the water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol in the moisturizing composition. When the compounding amount is less than 0.5 times by weight, the resultant base does not become a solubilized state, and when it is more than 100 times by weight, the effects of the invention cannot be expected. It is possible to previously compound, into this water, water soluble or dispersible component(s) such as known surfactant(s) or moisturizing agent(s). There is no particular limitation about processes for preparing the solubilized base of the invention, and it can, for example, be obtained by adding water to the moisturizing composition under stirring. The solubilized base of the invention can be used as a base for solubilized aqueous products which are expected to have moisture retainability. As such aqueous products, there can be mentioned cosmetics (skin lotions, cosmetic essences, etc.), etc.
The invention still further relates to a cosmetic which comprises the moisturizing composition according of the invention and other raw material(s) for cosmetics.
This cosmetic includes creams, liquid creams, skin lotions, cosmetic essences, cleansing gels, and further includes skin care cosmetics such as moisture gels and packs, and makeup cosmetics to which moisturizing effect is expected such as emulsion type foundations, emulsion eye shadows and nail treatments.
As the other raw materials for cosmetics, there can be mentioned oily substances (the same ones as in the viscous or gel-like base of the invention), surfactants (anionic, cationic, nonionic, amphoteric), mucilaginous substances (or water soluble macromolecules) (tragacanth gum, quince seed gum, xanthane gum, sodium alginate, cellulose derivatives, polyvinyl alcohol, sodium polyacrylate, carboxyvinyl polymers, polyethylene oxide, bentonite, etc.), powders (talc, kaolin, zinc white, titanium dioxide, mica, precipitated calcium carbonate, heavy calcium carbonate, calcium secondary phosphate, etc.), medicines (vitamins, hormones, antihistaminics, astringents, amino acids, etc.), ultraviolet absorbers, sequestering agents (EDTA sodium salt, etc.), other moisturizing agents (sodium hyaluronate, etc.), antioxidants, pH-adjusting agents, pigments and dyes, perfumes, antiseptics, water, etc. These other raw materials for cosmetics can be used alone or in combination of two or more.
It is suitable that the rate of the moisturizing composition in the cosmetic is 1 to 95% by weight, preferably 2 to 90% by weight in terms of the total content of the trihydric or more water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol in the cosmetic. When the rate is less than 1% by weight, the effects of the invention cannot be expected.
There is no particular limitation about processes for preparing the cosmetic of the invention, and it can, for example, be prepared by compounding at least one of the oily substance and water, and other raw materials for cosmetics into the moisturizing composition under stirring.
The invention also relates to an external preparation which comprises the moisturizing composition of the invention and other raw material(s) for external preparations.
This external preparation includes quasi-drugs, and lotion-like external preparations, ointments, gel agents, etc. which are medicines, for skin inflammations accompanied by the dryness of the skin such as chaps, cracks, itches and atopic dermatitis.
The other raw materials for external preparations include pharmaceutically effective ingredients and base components for external preparations.
As the base components for external preparations, there can be mentioned oily substances (the same ones as in the viscous or gel-like base of the invention), surfactants (anionic, cationic, nonionic, amphoteric), mucilaginous substances (or water soluble macromolecules) (tragacanth gum, quince seed gum, xanthane gum, sodium alginate, cellulose derivatives, polyvinyl alcohol, sodium polyacrylate, carboxyvinyl polymers, polyethylene oxide, bentonite, etc.), powders (talc, kaolin, zinc white, titanium dioxide, mica, precipitated calcium carbonate, heavy calcium carbonate, calcium secondary phosphate, etc.), pH-adjusting agents, antiseptics, colorants, water, etc. These other raw materials for external preparations can be used alone or in combination of two or more.
It is suitable that the rate of the moisturizing composition in the external preparation is 1 to 95% by weight, preferably 2 to 90% by weight in terms of the total content of the trihydric or more water soluble polyhydric alcohol, lecithin and 3-methyl-1,3-butylene glycol in the external preparation. When the rate is less than 1% by weight, the effects of the invention cannot be expected.
There is no particular limitation about processes for preparing the external preparation of the invention, and it can, for example, be prepared by compounding a pharmaceutically effective ingredient and base component(s) for external preparations into the moisturizing composition under stirring.